<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script>
		
		function a() {
			document.write(77);
			a();//堵塞
			document.width(999)
		}

		function b() {
			document.write(888);
			a();
		}

		a();
		document.write(6666);



	</script>
</head>
<body>
	
</body>
</html>